Janus Photoelectrocatalytic Filter for Sustainable Water Decontamination

Abstract

Herein, we conceive a Janus photoelectrocatalytic filter (Sb-Fe/MXene) by depositing Sb single-atoms (Sb-SA) and Fe nanoclusters (Fe-NC) decorated MXene mixture on either side of Ni-foam substrate, respectively, which realized sustainable and efficient generation of hydrogen peroxide (H2O2) and hydroxy radical (•OH) without any chemical input. Photocatalytic-side ensures that the accumulated holes at Ti vacancies neighboring the Sb-SA promote the 4e− water oxidation reactions to produce O2, while the Sb-SA sites collect electrons forming reducing centers for non-sacrificial H2O2 production via the 2e− oxygen reduction reaction. Electrocatalytic-side guarantees the circulation of ≡Fe(III)/≡Fe(II) by continuously exposing“fresh” reactive sites by dissociating H2O2 on the ≡Fe(II). This further prohibits iron sludge accumulation with an enhanced remedy of micropollutants, even under neutral conditions for wastewater. The collaborative effect between photochemistry and electrochemistry establishes a strategy for energy conversion and environmental remediation using a Janus photoelectrocatalytic filtration system.

Keywords: Janus filter, hydrogen peroxide, hydroxy radical, photoelectrocatalytic process, water decontamination